Long QT Syndrome

What is Long QT Syndrome?

Long QT syndrome (LQTS) is a type of conduction disorder. A conduction disorder is a problem with the electrical system that controls your heartbeat.

The term “long QT” refers to a problem with the pattern seen on an electrocardiogram (ECG). An ECG is a test that detects and records your heart’s electrical activity. Information from the ECG is mapped on a graph so your doctor can study your heart’s electrical activity. Each heartbeat is mapped as five separate electrical waves: P, Q, R, S, and T. (See more under "Long QT Syndrome" in the Invisible Illness category of my blog.)

The electrical activity that occurs between the Q and T waves is called the QT interval. This interval shows electrical activity in the heart’s lower chambers, called the ventricles. Normally the time between the Q wave and the T wave is about a third of each heartbeat cycle. However, in people who have LQTS, the QT interval lasts longer than normal.

What causes long QT syndrome?

LQTS is often inherited, which means you are born with the condition and have it your whole life. You also can acquire LQTS. This means you are not born with the disorder but develop it during your lifetime.

The following factors can raise your risk of LQTS:

- A family history of LQTS, or if someone in your family has had unexplained fainting or seizures, drowning or near drowning, or unexplained sudden death
- Heart conditions such as cardiomyopathy and congenital heart defects
- Medical conditions, such as eating disorders, thyroid disease, or serious diarrhea or vomiting, that cause low blood levels of potassium, magnesium, or calcium
- Medicines that affect how your heart’s ion channels work, including some antibiotics, antidepressants, and antihistamines
- Sex: LQTS is more common in women than men. Women who have LQTS are more likely to faint or die suddenly from the disorder during menstruation and shortly after giving birth.

Symptoms of LQTS may include:

- Fainting, which may happen during physical or emotional stress, and may include fluttering feelings in your chest before fainting
- Drowning or near drowning, which may be due to fainting while swimming
- Noisy gasping while sleeping
- Seizures

To diagnose long QT syndrome, your doctor will ask about your medical history, your family’s medical history, your symptoms, and what medicines you take. They will perform a physical exam and may order one or more tests:

- Blood tests can check your electrolyte and thyroid hormone levels.
- Genetic testing will look for changes in your genes that may cause LQTS and find out which type of LQTS you have.
- Heart tests measure your heart’s electrical activity. An ECG is the most common test used to diagnose LQTS. Because your QT interval may change from time to time, you may need to have several ECGs over a period of days or weeks or use a Holter monitor. You may also need a stress test to measure your heart rhythm while your heart is working hard and beating fast.

How is it treated and managed?

The goal of treating LQTS is to prevent arrhythmias and fainting spells. Treatment isn’t a cure for the disorder and may not restore a normal QT interval. However, treatment greatly lowers the risk of life-threatening problems.

Treatment may include:

- Lifestyle changes: Your doctor may ask you to avoid things that can cause problems with your heart rhythm, such as swimming and other vigorous physical activity, sudden loud noises such as an alarm clock, stressful situations, and some medicines. Ask your doctor about eating more potassium-rich foods (such as bananas) or taking potassium supplements daily.
- Medicine: You may need beta blockers to prevent your heart from beating faster in response to physical or emotional stress. If you have low electrolyte ion levels, your doctor may give you magnesium or potassium through your veins.
- Medical devices: Your doctor may recommend a device such as a pacemaker or implantable cardioverter defibrillator to help control your heart rhythm.
- Surgery: You may need surgery to cut the nerves that cause dangerous heart rhythms. This keeps your heart beating at a steady pace and lowers the risk of arrhythmias caused by stress or exercise.

Thank you.

Love and light! 💜

Leah xo